Cbl-b deficiency diminishes CD28 dependence of T cell activation and enhances susceptibility to autoimmune disease

Yungping J. Chiang1#, Hemanta K. Kole1#, Karen Brown2, Mayumi Naramura1, Shigetomo Fukuhara3, Ren-Ju Hu1, Ihn Kyung Jang1

J. Silvio Gutkind3, Ethan Shevach2, Hua Gu1

1: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, MD 20852, USA

2: National Institutes of Health, Bethesda, MD 20892, USA

3: Oral and Pharyngeal Cancer Branch, NIDCR, National Institutes of Health, Bethesda, MD 20892, USA

#: These authors contributed equally to this work.

Correspondence address:

Hua Gu, Ph.D

Laboratory of Immunology

National Institute of Allergy and Infectious Diseases

National Institutes of Health

12441 Parklawn Drive, Rm125

Rockville, MD 20852

USA

Tel: (301) 402 4595

Fax:(301) 594 2522

E-mail:

Supplement Figure legends

Suplement Figure 1 Total tyrosine phosphorylation in Cbl-b-/- T cells. Purified T cells were stimulated as indicated. Total phosphotyrosine was visualized using anti-phosphotyrosine antibody (4G10).

Supplement Figure 2 Actin-polymeryzation of anti-CD-3 antibody-stimulated Cbl/b-/- T cells. Cells were purified as described in the methods. T cells are visualized by green color and F-actin by red color. Arrows indicate the F-actin patches. The white bar in the upper-left panel represents 10 mm scale.

Materials and methods: Cover glass was coated with anti-CD3e antibody (10mg/ml) and treated with poly-L-lysine to enhance cell attachment. Purified T cells were activated on the treated cover glasses for 15-60 minutes at 37oC. Cells were fixed with 3% paraformaldehyde, surfaced stained with biotinylated anti-CD4/CD8 antibodies, followed with streptavidin-FITC. After membrane permeabilization with 0.1% Triton X-100, cells were stained with 1 U/ml Texas Red-conjugated phalloidin (Molecular Probes). Samples were examined under confocal microscopes (Bio Rad and Olympus). Shown are the samples stimulated with anti-CD3e antibody for 45 min.

Supplement Figure 3 Analysis of Vav Cbl-b association in T cells. The association of Vav and Cbl-b is demonstrated by co-immunoprecipitation. Cells were stimulated with anti-CD3e and anti-CD28 antibodies as indicated, and Vav and Cbl-b complexes in the cell lysates were immunoprecipitated using anti-Vav and anti-Cbl-b antibodies, respectively. Co-immunoprecipitated Vav and Cbl-b protein on the same blots were sequentially probed with anti-Cbl-b and anti-Vav antibodies. IP: immunoprecipitation.

2